Efficient block-based video encoder embedding a Wiener filter for noisy video sequences

摘要

Since pre-filtering removes camera noise and improves coding efficiency dramatically, its efficient implementation has been an important issue in video sequence coding. Based on the approximated generalized Wiener filtering and two-dimensional discrete cosine transform (DCT) factorization, this paper introduces a novel pre-filtering scheme that is performed inside a video encoder. The proposed pre-filtering is performed, by scaling the DCT coefficients of original image blocks for intra block coding and those of motion-compensated error blocks for inter block coding, respectively. Even though the pre-filtering operation is embedded in a video encoder, its additional computational complexity is marginal for given signal-to-noise ratio (SNR) estimates, and the overall architecture of the conventional video encoder is maintained. Notwithstanding its simplicity, the proposed pre-filtering scheme gives good filtering and coding performance for noisy video sequences.